四轴车辆全轮转向的最小转向半径模式研究

The Smallest Steering Radius Mode for All-Wheel Steering of Four-Axle Vehicle

通过调整双前桥转向传动机构以适应四轴车辆的全轮转向,研究得出转向中心线由3、4桥中心移至2、3桥中间且靠近3桥对车辆转向特性的影响可以忽略.在双前桥转向的基础上,以降低轮胎磨损、减小转弯半径为目标设计了四轴车辆最小转弯半径模式的控制算法.另外,为减小后两桥车轮向外滚出让驾驶员有摆尾感觉,在控制输出时加入了定延时.仿真结果表明所设计的控制器提高了四轴车辆的机动性,并且有效地改善了摆尾现象.

Double-front-axle steering mechanism was often used in four-axle vehicle. By adding electro-hydraulic power steering system to the third and the forth axles, it easily becomes an all- wheel steering vehicle. The change which needs the center line of steering must move from the center of the third axle and the forth axle to the middle between the second axle and the third axle. The research shows that this move has less effect on the characteristic of steering. Based this point, a controller was designed to reduce the radius of steering and reduce the rub of tire. Moreover, in order to diminish the fishtailing of rear axle tires, a constant delay time was applied to the output of the controller. All simulation results show that the controller can improve the flexibility of four-axle vehicle and restrain the fishtailing phenomenon effectively.